1. Field of the Invention
The present invention relates to an image-capturing device such as an electronic camera that records an image captured by employing an image sensor, and more specifically, it relates to an image-capturing device that records image data into a recording medium such as a memory card that can be detachably mounted at the main body of the image-capturing device.
2. Description of the Related Art
There are electronic cameras that store image data obtained through a photographing operation into a portable memory such as a memory card loaded in a slot in the related art. In such a camera, image data obtained from a photographing operation can not be stored if the storage capacity of the portable memory has become low or if no portable memory is loaded. As a means for solving this problem, Japanese Laid-Open Patent Publication No. H 5-56322 and Japanese Laid-Open Patent Publication No. H 10-336572 each disclose an electronic camera that temporarily stores photographic image data into an internal memory within the electronic camera if the recording capacity of the portable memory loaded in the slot is not sufficient or if no portable memory is loaded in the slot.
In addition, there is an electronic camera in the known art having a wireless communication circuit, which transfers photographic image data to an external device through a wireless line to store the image data in an external memory connected to the external device.
However, there is a problem with the electronic camera that temporarily stores photographic image data into the internal memory if the portable memory, which must be loaded in the main body for use, is not available, in that since the storage capacity of the internal memory is smaller than the storage capacity of the portable memory and thus there is a limit to the volume of image data that can be stored in the internal memory, the number of photographs that can be taken after the portable memory becomes unavailable is also limited. Since it is not very likely that the photographer has a spare portable memory for image data storage such as a memory card, which is more expensive than silver halide film and the like and also, the availability of such portable memory products is relatively limited, it is expected to take the photographer a considerable length of time to acquire a new portable memory and utilize it in the electronic camera, and thus, the problem of the limited number of photographs that can be taken described above can become a serious concern.
While it is conceivable to employ a memory with a large storage capacity for the internal memory, the cost of nonvolatile memory with a large storage capacity (such as flash memory) is much higher than the cost of volatile memory and, for this reason it cannot be readily used in an electronic camera which is a commercial product.
In the electronic camera that transfers photographic image data to an external device through a wireless line, on the other hand, the transmission of the photographic image data is disabled and the subsequent photographing operation is also disabled if communication with the external device becomes disabled, and thus, there are concerns that the photographic image data cannot be used and that the photographer may miss good photo opportunities.